Field of Invention
The present invention relates to a firearm accessory attachment system of a firearm, and more particular to a KeyMod mount, which provides a quick and precise attachment to be detachably mounted at the firearm.
Description of Related Arts
Conventional rail systems, such as “Picatinny rail system, have evolved in the firearm industry from a military standard. The conventional rail system generally provides a rail comprising a plurality of T-shaped cross sectional raised ridges formed at the firearm, and an adapter provided at the accessory, wherein the accessory can be mounted at the rail by transversely sliding the adapter at the rail and fastening the adapter at the rail via a bolt. However, the conventional rail system has several drawbacks. The rail will only enable the accessory to be mounted at the firearm at the transverse direction. It is not ergonomic for a user to hold the firearm and mount the accessory to the rail in a transverse direction to the discharge axis of the firearm. In addition, the rail profile with the raised ridges will substantially increase the overall weight of the firearm. More importantly, the rail cannot provide a quick and precise attachment for the firearm because the adapter must be fastened with the rail by the bolt.
A “KeyMod” rail system is an improved system superior to the conventional rail system. The KeyMod mounting arrangement generally comprises a plurality of KeyMod mounting slots provided at the firearm and a KeyMod mounting nut provided at the accessory. In particular, each of the mounting slots, which is extended along the discharge axis of the firearm, has a keyhole configuration defining an enlarged slot portion with larger diameter and a narrower slot portion extended therefrom, wherein the slot is chamfered on the backside. Therefore, the mounting nut can be disposed in the enlarged slot portion and slid to the narrower slot portion. Then, the mounting nut can be fastened at the narrower slot portion by a bolt to lift the mounting nut at the backside of the mounting slot in order to secure the accessory at the firearm. The KeyMod rail system can solve the existing problems by providing an ergonomic mounting way to mount the accessory at the firearm corresponding to the discharge axis thereof, and by substantially reducing the overall weight of the firearm incorporating with the KeyMod mounting slots. However, the KeyMod rail system has several drawbacks.
The alignment between the mounting nut and the enlarged slot portion of the mounting slot must be precise. Especially when two or more mounting nuts are provided at the accessory, the user must correctly align the mounting nuts with the enlarged slot portions of the mounting slots respectively. Since the mounting nuts are movable, the user must hold the mounting nuts stationary before the mounting nuts are plugged into the enlarged slot portions of the mounting slots. It is worth mentioning that the mounting nuts can only be stationary or locked after the mounting nuts are lifted by the bolts to couple at the narrower slot portions of the mounting slots. In other words, the KeyMod rail system provides a displeasing mounting operation comparing with the conventional “Picatinny rail system or “Weaver” rail system. Furthermore, the KeyMod rail system still cannot provide a quick and precise attachment for the firearm because the mounting nut must be fastened with the mounting slot by the bolt.
The two different rail systems are commonly found in a handguard to give more room for attaching the accessory to the firearm. Accordingly, the handguard is mounted at a front portion of a firearm to serve not only as a guard to protect the barrel but also as a hand grip for the user to grip the firearm. The handguard has a polygonal cross section and defines a plurality of longitudinal faces, wherein conventional rail system is formed on the top longitudinal face of the handguard while the KeyMod mounting slots are formed at the rest of the longitudinal faces. The KeyMod mounting slots serve as heat dissipating holes formed in series on each longitudinal face of the handguard to dissipate heat from the barrel since it may become very hot when firing. Therefore, the accessory can be mounted to the handguard by either the conventional rail system or the KeyMod rail system. However, the existing handguard has several drawbacks.
Since the handguard is made of metal for heat dissipation, the edges of the KeyMod mounting slots will be sharp enough to cut the skin of the user especially by the recoil force of the firearm when the user grips the handguard. More importantly, the handguard will burn the hand of the user when it becomes extremely hot. Therefore, a handguard cover is found in the market to solve the above mentioned problems. The handguard cover, which is made of soft material such as rubber, comprises a cover panel and an elastic plug pressed into one of the KeyMod mounting slots in order to cover the cover panel on the exterior side of the longitudinal face of the handguard. This handguard can substantially provide a comfortable touch and can block the heat from the barrel to burn the hand of the user when the user grips the handguard. However, the handguard cover is held at the handguard by the elastic force of the elastic plug at the KeyMod mounting slot, such that the handguard cover can be easily detached from the handguard. In addition, the handguard cover can only cover two or more KeyMod mounting slots at the same longitudinal face of the handguard. In other words, if the user wants to cover two KeyMod mounting slots at different longitudinal faces of the handguard, two handguard covers are required. More importantly, when the KeyMod mounting slot is covered by the handguard cover, the accessory cannot be mounted at the same KeyMod mounting slot.